Drunk-driving teen Ethan Couch threw a party before running

Ethan Couch killed 4 people when he was drunk driving in 2013 ( ATTORNEY GENERAL OF THE STATE OF JALISCO)

A teenager in Texas who was serving probation for killing four people in a drunk-driving accident is said to have had a "going away party" before going on the run.

Before Ethan Couch, an 18-year-old made famous in 2013 by his "affluenza" defence, disappeared on December 10, he and his mother Tonya planned to flee, according to CBSnews.com

The duo were apprehended by Mexican authorities on Monday evening (local time), and Couch had dyed his blonde hair dark brown.

Couch has not yet been turned over to American authorities.

It's believed Ethan Couch fled after a video that surfaced online showing the teen at a party playing beer pong. Investigators began searching for the pair after Couch failed to keep a mandatory appointment with his probation officer on December 10.

The teen's sentence caused controversy in 2013 after his lawyer argued in court that he didn't understand consequences due to his parents' wealth, a syndrome the lawyer called "affluenza".

In June 2013, at age 16, Couch was driving drunk and speeding when he crashed into an SUV on the side of the road, killing four people and injuring nine others. Many of the victims had been helping the woman whose SUV had stalled, others were in Couch's pickup truck. The 16-year-old's blood-alcohol level was three times the legal limit for an adult and there were traces of Valium in his system, CBSnews.com reports.

He pleaded guilty to four counts of intoxication manslaughter and two counts of intoxication assault causing serious bodily injury. When he was sentenced him to 10 years' probation, there was widespread outrage.